Flexible films for use as food wraps have been developed and improved over time. Such food wraps are typically called food grade wrap films. There are many criteria that consumers require in a flexible food grade wrap film. First, it is important for the film to be strong and yet easily torn when brought in contact with a cutter bar as found in the standard containers used for containing and dispensing flexible food grade wrap film. Second, it is important for the film to be flexible so that it molds easily around a container or object to be covered or wrapped. Third, the film must be somewhat tacky to seal around the container or object, but at the same time not be so tacky that it will too aggressively stick to itself, making the film difficult to unwind from a roll due to “blocking”, or too unruly making it difficult to place the film at a desired location during use.
For general background, U.S. Pat. No. 5,399,426 to Koch, et al. discloses monolayer and multilayer film structures having at least one layer of a polymer blend comprising at least one branched polymer (e.g., low density polyethylene (LDPE) or ethylene/vinyl acetate copolymer (EVA)) and at least one linear polyethylene (e.g., LLDPE). The film structures are described as having a good overall balance of properties, including high ultimate elongation, excellent load retention and good machine direction tear. However, no mention is made of any particular feature in the film that addresses the concern that the film not be so tacky that it will easily stick to itself, causing “blocking” when wound or preventing easy placement of the film in a desired location. U.S. Pat. No. 5,948,493 to attempts to solve this problem with a plastic wrap that exhibits little or no cling until such time as it is applied to an article or other target surface. An adhesive layer formed on one side of the sheet of olefinic polymer is exposed to a treatment that superficially oxidizes or cross-links the outer layer of the adhesive material to form a film that exhibits greatly attenuated adhesion. This cross-linked outer layer is disruptable as the wrap is applied and stretched or otherwise deformed in a manner that uncovers the adhesive material and endows cling properties on at least localized areas of the wrap.
We have discovered an alternative, simpler, cost-effective structure for a food grade film wrap (and a method for making it) containing a textured structure in combination with other film features, that is flexible, transparent, translucent or opaque, strong yet easily torn off from the roll using a cutter bar, and that is sufficiently tacky to seal around a container or object but not too tacky to cause “blocking”. The method of making such a film is efficient from a production standpoint, allowing the extrusion of a thicker film gauge; cost-effective, allowing a final thinner film gauge; and having a consumer perceivable texture.